Added documentation on challenges
Added documentation on challenges

WhiteHatCP/wrath-ctf-framework,WhiteHatCP/wrath-ctf-framework,DeltaHeavy/wrath-ctf-framework,WhiteHatCP/wrath-ctf-framework,WhiteHatCP/wrath-ctf-framework,DeltaHeavy/wrath-ctf-framework,DeltaHeavy/wrath-ctf-framework,DeltaHeavy/wrath-ctf-framework